Planetary conjunction refers to the simultaneous appearance of multiple planets in a small area of the sky. In ancient times, people could only observe five planets—Mercury, Venus, Mars, Jupiter, and Saturn—with the naked eye. If all five planets appeared simultaneously within a small area of the sky (such as the 45° range specified by the Qing Dynasty's Imperial Observatory), it was called the "Five Planet Conjunction" and was traditionally regarded as a "divine omen." In reality, however, since the orbital planes of the planets revolving around the sun are relatively close (with a maximum difference of about 10°) and their orbital periods vary, with some moving faster and others slower, it is a natural phenomenon for the planets to gather and disperse from each other as seen from Earth, without any special significance. The claim of "divine omens" was just flattery from courtiers to the emperor in the feudal era and was completely unfounded.
Some people also claim that the gravitational overlap caused by planetary conjunctions could lead to disasters on Earth, but this is also completely unscientific. Except for the sun and the moon, the tidal forces of other celestial bodies on Earth are extremely weak. Venus, the most influential planet, exerts a tidal force on Earth that is only two-hundredths of the tidal force exerted by the moon. The tidal forces of the moon and the sun cause tides on Earth, with high and low tides typically reaching 2–5 meters, and the highest reaching over 10 meters. By comparison, even if all the planets lined up in the same direction, their gravitational changes could only cause a 0.4-millimeter rise in Earth's sea level, which is far from capable of causing any disasters.